The present invention relates to immunoadjuvants that include phytol or a phytol derivative and the use of the immunoadjuvants in a pharmaceutical formulation to effect treatment by augmenting immunogenicity and effectiveness of vaccines.
Vaccines are used to provide effective immunity to prevent infection and even cancer. With the introduction of widespread immunization in the last century, diseases such as diphtheria, tetanus, polio, small pox, and pertussis have been significantly reduced if not eliminated. Moreover, new generations of vaccines are constantly being sought after for treatment of diseases such as AIDS, hepatitis, and herpes.
Vaccines are meant to stimulate the individual's specific and non-specific immune responses. Vaccines are accompanied by an adjuvant which can increase the efficacy of the vaccine by a variety of actions, including retaining the vaccine in the body or at the site of injection for a significantly long period of time, eliminating or reducing degradation and/or excretion, and recruiting or directing macrophages and other antigen-presenting cells (APCs) to augment humoral and/or cellular immune responses to the pathogen or associated antigens. However, many adjuvants, while effective, are also often toxic to humans. These adjuvants can cause severe adverse inflammatory reactions. Therefore, while adjuvants can be effective in enhancing the immunogenicity of the antigens in the vaccines, they can also induce severe side reactions.
The only adjuvant currently accepted by the FDA for use in humans is aluminum hydroxide or alum. While this adjuvant presents fewer instances of adverse reactions, it is not as effective in inducing humoral or cellular immune responses as other adjuvants, such as incomplete Freund's adjuvant (IFA) or complete Freund's adjuvant (CFA, which is IFA plus mycobacterial components). Both Freund's adjuvants, for example, are used in animals (other than humans) to produce antibodies for treatment and diagnosis under strict regulations of USDA and Public Health Service (PHS). While CFA/IFA are not approved for use in humans because they can be quite toxic to certain individuals, they are still considered as the gold standard in adjuvant formulation. In countries other than the United States, IFA is used in many vaccine formulations.
A safer, non-toxic, non-carcinogenic adjuvant which elicits an enhanced immune response for the antigens in the vaccine formulation would be of immense value to both human and animal welfare. The present invention addresses the above described problems and provides a variety of benefits and advantages.